1. Field of the Invention
The present invention relates to a thin film transistor, a method of manufacturing the same, a display apparatus having the same and a method of manufacturing the display apparatus. More particularly, the present invention relates to a thin film transistor for an array substrate of a display apparatus, a method of manufacturing the thin film transistor, a display apparatus having the thin film transistor and a method of manufacturing the display apparatus.
2. Description of the Related Art
In general, a liquid crystal display apparatus includes an array substrate and a color filter substrate. The array substrate includes a thin film transistor acting as a switching device and a pixel electrode electrically connected to the thin film transistor to receive a pixel voltage. The color filter substrate includes a common electrode.
The thin film transistor includes a gate line formed with a gate electrode, a gate insulating layer for the gate line, a channel pattern on the gate insulating layer, a data line formed with a source electrode and a drain electrode.
Recently, signal lines such as the gate line, the data line, etc., have become longer due to an increase in the size of the liquid crystal display apparatus. As a result of the signal lines being longer, signals applied to the signal lines are delayed or distorted. In order to prevent the delay and distortion of the signals, the signal lines include a low-resistance metal such as aluminum (Al), aluminum alloy and the like.
However, an undesirable irregularity forms on the low-resistance metal (e.g., aluminum) when heat is applied. More specifically, when the aluminum is heated to a high temperature of about 180 degrees, concave-convex portions are formed on a surface of the aluminum due to compressive stress between aluminum atoms of the aluminum. Where the data line includes aluminum, the aluminum makes contact with a conductive adhesive layer (which may be an N+ doped amorphous silicon layer under the data line) that enhances the contact resistance between the aluminum and the conductive adhesive layer. The enhanced contact resistance causes the aluminum to disperse into the conductive adhesive layer under high temperature, forming the irregularity.
Further, when the conductive adhesive layer is etched to form a channel layer, the conductive adhesive layer pattern is exposed outside the source electrode, the drain electrode or the data line. As a result, an undesirable after-image occurs on the liquid crystal display apparatus.
A method of forming a display apparatus without the above problems is desired.